Project description:BMA64 rrp6 delta::HIS3 vs BMA64 WT (Mat a), grown at 30°C to OD 0.6 in YPD. BMA64 rrp6 delta::URA3, trf4 delta::KAN vs BMA64 WT, grown at 30°C to OD<0.6 in YPD. Keywords: other
Project description:Recent studies have revealed that eukaryotic genomes are pervasively transcribed by RNA polymerase II, producing a plethora of non-coding RNAs which frequently overlap protein-coding genes. Despite the fact that overlapping transcription is well known to repress transcription initiation from downstream promoters, the mechanism behind this phenomenon has remained elusive. It was proposed that transcriptional interference relies on the act of transcription rather than the RNA itself to block access of the transcription machinery to downstream promoters. Here, we use the fission yeast Schizosaccharomyces pombe to demonstrate that an RNA and chromatin-dependent mechanism is responsible for transcriptional interference. This relies on co-transcriptional recruitment of the histone deacetylase Clr3 to nascent non-coding RNA, leading to formation of hypoacetylated chromatin and repression of the downstream protein-coding gene. Our findings highlight the unexpected requirement for RNA as well as trans-acting protein factors in mediating the repressive effects imposed on gene expression through overlapping non-coding transcription.
Project description:BMA64 rrp6 delta::HIS3 vs BMA64 WT (Mat a), grown at 30°C to OD 0.6 in YPD. BMA64 rrp6 delta::URA3, trf4 delta::KAN vs BMA64 WT, grown at 30°C to OD<0.6 in YPD.
Project description:We used tiling microarrays to identify up-regulated genes in mmi1 delta cells. Because these cells grow very poorly due to misexpression of mei4 gene, we combined mmi1 delta mutation to a partial deletion of mei4. Cells carrying only mei4 partial deletion were also analyzed in our transcriptomics to verify that variations observed in mmi1 delta cells are not due mei4 mutation. RNA levels from S. pombe cells with only mei4 partial deletion (SPV481) or with mei4 partial deletion in combination with mmi1 delta deletion (SPV903) were compared to wild type cells (SPV8), using Affymetrix S. pombe Tiling 1.0FR microarrays. Two biological replicates were analyzed for each experiment.
Project description:We studied the differences in RNA accumulation profiles of an rrp6-null mutant and compared it to RNA accumulation in rrp6 catalytic mutants as well as dis3 mutants using RNA-Seq. Rrp6 and Dis3 are exosome exoncleases, therefore this study was used to determine their target RNAs We examined 3' end RNA processing changes by RNA-Seq in wild type, rrp6Δ and rrp6-cat mutants. Libraries were made by 3' adapter ligation
Project description:Expression profiling of cid14 delta and air1 delta cells shows that efficient silencing of a few heterochromatic genes depends on Cid14 and/or Air1.